Maple underside leaf miner

The maple underside leaf miner (Lithocolletis aceriella), also known as Phyllonorycter aceriella, belongs to the family Gracillariidae within the order Lepidoptera. This small moth is a common pest that specifically targets various species of maple trees, significantly affecting their foliage health during the growing season.

This pest mainly attacks species of the genus Acer. While damage is often localized, high populations in nursery settings or urban landscapes can cause substantial defoliation. The presence of the miner not only affects the aesthetic appeal of the trees but also interferes with the carbon assimilation process.

The life cycle of the moth consists of complete metamorphosis. Overwintering occurs typically as a pupa within the fallen leaf litter. In the spring, adult moths emerge to mate and lay eggs on the underside of maple leaves. Upon hatching, the larvae mine into the leaf tissue to feed and grow through several instars.

The damage caused by the larvae is characterized by blotch mines on the underside of the leaves. As the larvae consume the parenchyma, the epidermis remains intact, resulting in discolored patches. Heavy infestations cause premature browning and shedding of leaves, which can induce stress in the host tree.

Integrated Pest Management (IPM) is essential for controlling Lithocolletis aceriella. Sanitation is the most critical cultural practice, involving the collection and disposal of infested leaf litter before the next season. Chemical control, using systemic insecticides, can be effective if applied during the period when larvae are active.